Initial checkin of lldb code from internal Apple repo.


git-svn-id: https://llvm.org/svn/llvm-project/llvdb/trunk@105619 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/source/Target/ExecutionContext.cpp b/source/Target/ExecutionContext.cpp
new file mode 100644
index 0000000..e79f8c2
--- /dev/null
+++ b/source/Target/ExecutionContext.cpp
@@ -0,0 +1,107 @@
+//===-- ExecutionContext.cpp ------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//
+
+//
+//===----------------------------------------------------------------------===//
+
+
+#include "lldb/Target/ExecutionContext.h"
+#include "lldb/Target/ExecutionContextScope.h"
+#include "lldb/Target/StackFrame.h"
+#include "lldb/Target/Process.h"
+#include "lldb/Target/Target.h"
+#include "lldb/Target/Thread.h"
+
+using namespace lldb_private;
+
+ExecutionContext::ExecutionContext() :
+    target (NULL),
+    process (NULL),
+    thread (NULL),
+    frame (NULL)
+{
+}
+
+ExecutionContext::ExecutionContext (Target* t, bool fill_current_process_thread_frame) :
+    target (t),
+    process (NULL),
+    thread (NULL),
+    frame (NULL)
+{
+    if (t && fill_current_process_thread_frame)
+    {
+        process = t->GetProcessSP().get();
+        if (process)
+        {
+            thread = process->GetThreadList().GetCurrentThread().get();
+            if (thread)
+                frame = thread->GetCurrentFrame().get();
+        }
+    }
+}
+
+ExecutionContext::ExecutionContext(Process* p, Thread *t, StackFrame *f) :
+    target (p ? &p->GetTarget() : NULL),
+    process (p),
+    thread (t),
+    frame (f)
+{
+}
+
+ExecutionContext::ExecutionContext (ExecutionContextScope *exe_scope_ptr)
+{
+    if (exe_scope_ptr)
+        exe_scope_ptr->Calculate (*this);
+    else
+    {
+        target  = NULL;
+        process = NULL;
+        thread  = NULL;
+        frame   = NULL;
+    }
+}
+
+ExecutionContext::ExecutionContext (ExecutionContextScope &exe_scope_ref)
+{
+    exe_scope_ref.Calculate (*this);
+}
+
+void
+ExecutionContext::Clear()
+{
+    target  = NULL;
+    process = NULL;
+    thread  = NULL;
+    frame   = NULL;
+}
+
+
+RegisterContext *
+ExecutionContext::GetRegisterContext () const
+{
+    if (frame)
+        return frame->GetRegisterContext();
+    else if (thread)
+        return thread->GetRegisterContext();
+    return NULL;
+}
+
+ExecutionContextScope *
+ExecutionContext::GetBestExecutionContextScope () const
+{
+    if (frame)
+        return frame;
+    if (thread)
+        return thread;
+    if (process)
+        return process;
+    return target;
+}